Novel nitriles and use as perfume chemicals

ABSTRACT

Novel nitriles based on the carbon skeleton of menthane are disclosed, having the structural formula  These compounds are useful in a variety of perfumery applications.

This invention relates to new and useful chemical compounds, useful as aperfume or as a component of perfumes. Specifically it relates tonitriles based on the skeleton of 1-methyl-4-isopropylcyclohexane. Inrecent years a trend in perfumery is observable in the direction of theuse of nitriles, which class of compounds has previously been ratherunexploited for perfumery purposes.

Besides the desirable olfactory properties of the nitriles for modernperfumery, most of the nitriles which have to date found acceptance inperfumery also possess desirable properties with respect to chemicalstability and resistance to discolouration in many applications, e.g. insoap and other cosmetic preparations, where many otherwise usefulperfumery chemicals are not stable. In particular3,7-dimethyl-6-octenenitrile, 3,7-dimethyl-2,6-octadienenitrile and also3-phenylacrylonitrile are useful in perfumery.

It is the object of the present invention to provide a novel class ofnitriles based on the carbon skeleton of1-methyl-4-isopropylcyclohexane. These novel nitriles are represented byformula I, wherein R₁ and R₂ represent hydrogen or an alkyl group ofabout 1 to 6 carbon atoms and the total carbon number of R₁ and R₂ is 6or less and wherein the dotted lines represent C-C double or singlebonds with the limitation that no more than one such double bond can bepresent in the six-membered ring and no more than one in the nitrilegroup containing side chain. It will be understood that the doublebonds, when present, must be so located as to satisfy the tetravalentcarbon concept. ##STR1## Examplary, but by no means all, compounds ofthe invention having the specified structure are:

3-(1-methyl-4-isopropylcyclohexyl-2)acrylonitrile

3-(1-methyl-4-isopropylcyclohexylidene-2)propanenitrile

2-n-hexyl-3-(1-methyl-4-isopropylcyclohexylidene-2)propanenitrile

2-methyl-3-(1-methyl-4-isopropylcyclohexenyl-2)-2-butenenitrile

3-(2-methyl-5-isopropylcyclohexenyl-1)-2-butenenitrile

3-(1-methyl-4-isopropenylcyclohexenyl-6)acrylonitrile

3-(3-methyl-6-isopropenylcyclohexenylidene-4)propanenitrile

It will be apparent that the novel nitriles can exist in a wide varietyof stereoisomeric forms and it is intended that these be included withinthe structural formulae. Whenever a general formula is presented orreferred to in the text or in the attached claims, it is intended toinclude all possible stereoisomeric forms of the compound. The novelnitriles can be prepared by methods known to the art. In a preferredmethod an oxo-compound of the general formula II wherein ##STR2## thedashed lines and R₁ are as described above, is reacted with a nitrilegroup-containing reagent, for example, cyanoacetic acid or its esters, acyanoalkylphosphonate or an alkylnitrile.

The oxo-compounds represented by formula II can be prepared by methodsknown to the art. In a preferred method d-,l - or a mixture of thed,l-forms of limonene is converted to p-1-menthene, i.e.1-methyl-4-isopropylcyclohexene, by partial hydrogenation for example astaught by Y. Kishida, Chem. Pharm. Bull. 8, 357-64 (1960).Hydroformylation of p-1-menthene using a method taught by Falbe,Synthesen mit Kohlenmonoxyde, Springer Verlag, Berlin (1967), pages3-72, leads to 2-formyl-p-1-methane. This is a method of preparingcompounds wherein R₁ is hydrogen.

Another preferred method of preparing the oxo-compound of formula IIwhere R₁ is an alkyl radical is by acylation of the p-1-menthene withacid anhydrides or other acid derivatives using the method described inBritish patent nr. 870.001. When using this method the oxo compoundretains a carbon-to-carbon double bond in the six-membered ring whichcan subsequently be hydrogenated, if desired.

An indirect method of preparing the oxo-compounds is by way of the Prinsreaction of alkenes with aldehydes using the method taught by Roberts inOlah, Friedel-Crafts and Related Reactions, Vol. 3, IntersciencePublishers, Inc., New York, 1964, pages 1175-1210, and specifically forp-1-methene by J. Colonge et al., Bull.Soc.Chim.Fr. 1960, 98.

By this method it is also possible to prepare a product which retains acarbon-to-carbon double bond in the six-membered ring. Other methods toprepare the compounds of formula II are by skeletal rearangements ofappropriately substituted β-pinene compounds for example by pyrolysis astaught by Bochwic et al., Bull.Acad.Polon.Ser.Sci.Chim. 13 (11-12),751-6 (1965) and by Watanabe, Nippon Kagaku Zasshi 81, 931 (1960), andof appropriately substituted 2-carene compounds by pyrolysis isdescribed by Ohloff, Chem.Ber. 93, 2673 (1960) and in the East GermanPat. Nos. 57.850 and 68.903, or by photochemical rearrangement cf.Kropp, J.Am.Chem. Soc. 89, 1126 (1967) and U.S. Pat. No. 3.507.761.These rearrangements lead to oxo-compounds which retain acarbon-to-carbon double bond in the six-membered ring as well as in theiospropyl structure.

The oxo-compounds which contain a carbon-to-carbon double bond in thesix-membered ring in the position β,γ to the carbonyl function can beconverted to the correpsonding compounds with the double bond in theα,β-position by methods known to the art, preferably by alkalineisomerization. In any of the structures, the carbon-carbon double bondscan be partially or fully hydrogenated by conventional hydrogenationmethods. The nitriles of this invention are prepared by reacting anoxo-compound of the formula shown above with a reagent containing anitrile group. One method known for this reaction is the Knoevenagelcondensation with cyanoacetic acid or esters thereof--cf. G. Jones inOrganic Reactions, John Wiley and Sons, Inc., New York, 1967, volume 15,p. 236-244--followed by decarboxylation. ##STR3##

The decarboxylation step can be performed by simple heating of theintermediate alkylidene cyanoacetic acids, but it is preferably carriedout in the presence of nitrogen bases such as pyridine, pyrimidine,morpholine, piperidine, triethanolamine, dimethylformamide and the like.Well known decarboxylation catalysts such as copper compounds, forexample Cu₂ O as taught by Fairhurst, Horwell and Timms, TetrahedronLetters 1975, p. 3843 can also be used. The alkylidene cyanoacetic estercan be saponified and decarboxylated simultaneously by treating withwater in the presence of dimethylformamide or dimethylsulfoxide asdescribed by Krapcho, Jahngen and Lovey, Tetrahedron Letters, 1973, p.957 and 1974, p. 1091.

Nitriles with saturated nitrogen containing side chains can convenientlybe prepared by performing the condensation of the oxo-compound withcyanoacetic esters in a hydrogen atmosphere in the presence of ahydrogenation catalyst as described by Alexander and Cope,J.Am.Chem.Soc. 66, p. 886 (1944).

It will be apparent that the condensation of the oxo-compounds withcyanoacetic acid or ester, followed by decarboxylation leads to nitrilesrepresented by the general formula I in which R₂ is hydrogen. It ispossible to introduce an alkyl group by direct alkylation of theintermediate alkylidenecyanoacetic ester. This alkylation is preferablycarried out in the presence of a strong base such as sodium hydride inan aprotic solvent such as dimethylformamide and an alkylhalide, R₂ X,wherein X can be chlorine, bromine or iodine. Saponification anddecarboxylation of the resulting desubstituted cyanoacetic ester yieldsnitriles in which R₂ is an alkyl radical. The reaction sequence can berepresented as follows: ##STR4## Another preferred method for thepreparation of the nitriles of the invention is the Wittig reaction ofthe oxo-compounds with a cyanoalkylphosphonate in the presence of abase, for example, with (EtO)₂ POCHR₂ CN as described in the German Pat.No. 1.108.208. Also useful is the two phase modification of thisreaction according to Piechucki, Synthesis 1974, p. 869 and to D'Incanand Seyden-Penne, Synthesis 1975, p. 516. The reaction is set forth inthe following scheme: ##STR5## The oxo-compounds can also be condenseddirectly with alkyl-nitriles in the presence of an alkaline catalystsuch as KOH. However this method is less attractive due to inferioryields in comparison with the other methods. Furthermore, some of theoxo-compounds, especially the aldehyde, are not sufficiently stableunder the reaction conditions employed. ##STR6## The starting materialfor preparing the oxo-compounds of formula II can be in a dextrorotatoryor levorotatory optical configuration or a mixture of the two. Dependingon the configuration of the starting material employed, the nitriles ofthe invention can exist in a variety of stereoisomeric forms. Since, forexample, the starting material, p-1-menthene, exists both in a (+) and a(-) optical configuration the same can be expected in the oxo-compoundsII derived from these p-1-menthenes. There is a possibility of eight2-formyl-p-menthanes derived from a d,l-mixture of p-1-menthenes. Theseare represented by the following structural formulae: ##STR7## It willalso be apparent, as shwon by the general formulae, that the nitriles ofthe invention which possess a double bond in the nitrogen-containingside chain, can exist in two isomeric forms with respect to the positionof the double bond relative to the nitrile group. This position caneither be α,β or β,γ- to the nitrile group. Furthermore in either ofthese positions, double bonds can exist in an E- or Z-configuration, sothat a total of 4 isomeric nitriles, represented by the formula'sXI-XIV, are possible with respect to the location and configuration ofthe double bond in the nitrile group containing side chain: ##STR8##

It will be further apparent that the compounds of the invention canexist in various stereoisomeric and enantiomorphic forms with respect tothe substituents on the six-membered ring depending on their orientationrelative to the plane of the ring. This can be illustrated by thereaction product of the cyanoacetic ester synthesis using2-formyl-p-menthane from d,l-p-1-menthene. As stated above there is apossibility of a mixture of eight 2-formyl-p-menthanes, III-X, derivedfrom a d,l-mixture of p-1-menthenes. Such a mixture, reacted withcyanoacetic acid followed by decarboxylation, yields a mixture which cancontain twelve isomeric nitriles and twelve enantiomorphs thereof. Theresulting 24 possible compounds are as follows:

(E)-3-((1R, 2R, 4R)-1-methyl-4-isopropylcyclohexyl-2)acrylonitrile

(E)-3-((1S, 2R, 4R)-1-methyl-4-isopropylcyclohexyl-2)acrylonitrile

(E)-3-((1R, 2S, 4R)-1-methyl-4-isopropylcyclohexyl-2)acrylonitrile

(E)-3-((1R, 2R, 4S)-1-methyl-4-isopropylcyclohexyl-2)acrylonitrile

(E)-3-((1S, 2S, 4S)-1-methyl-4-isopropylcyclohexyl-2)acrylonitrile

(E)-3-((1R, 2S, 4S)-1-methyl-4-isopropylcyclohexyl-2)acrylonitrile

(E)-3-((1S, 2R, 4S)-1-methyl-4-isopropylcyclohexyl-2)acrylonitrile

(E)-3-((1S, 2S, 4R)-1-methyl-4-isopropylcyclohexyl-2)acrylonitrile

(Z)-3-((1R, 2R, 4R)-1-methyl-4-isopropylcyclohexyl-2)acrylonitrile

(Z)-3-((1S, 2R, 4R)-1-methyl-4-isopropylcyclohexyl-2)acrylonitrile

(Z)-3-((1R, 2S, 4R)-1-methyl-4-isopropylcyclohexyl-2)acrylonitrile

(Z)-3-((1R, 2R, 4S)-1methyl-4-isopropylcyclohexyl-2)acrylonitrile

(Z)-3-((1S, 2S, 4S)-1-methyl-4-isopropylcyclohexyl-2)acrylonitrile

(Z)-3-((1R, 2S, 4S)-1-methyl-4-isopropylcyclohexyl-2)acrylonitrile

(Z)-3-((1S, 2R, 4S)-1-methyl-4-isopropylcyclohexyl-2)acrylonitrile

(Z)-3-((1S, 2S, 4R)-1-methyl-4-isopropylcyclohexyl-2)acrylonitrile

(E)-3-((1R, 4R)-1-methyl-4-isopropylcyclohexylidene-2)propanenitrile

(E)-3-((1R, 4S)-1-methyl-4-isopropylcyclohexylidene-2)propanenitrile

(E)-3-((1S, 4R)-1-methyl-4-isopropylcyclohexylidene-2)propanenitrile

(E)-3-((1S, 4S)-1-methyl-4-isopropylcyclohexylidene-2)propanenitrile

(Z)-3-((1R, 4R)-1-methyl-4-isopropylcyclohexylidene-2)propanenitrile

(Z)-3-((1R, 4S)-1-methyl-4-isopropylcyclohexylidene-2)propanenitrile

(Z)-3-((1S, 4R)-1-methyl-4-isopropylcyclohexylidene-2)propanenitrile

(Z)-3-((1S, 4S)-1-methyl-4-isopropylcyclohexylidene-2)propanenitrile

The ratio of nitrile isomers formed can be influenced by the reactionconditions employed and by the choice of starting material with respectto the optical configuration. According to the invention it was foundthat in the above mentioned Wittig-type reactions of the oxo-compoundswith cyanoalkyl phosphonates predominantly the isomers withα,β-unsaturated nitrile side chains are formed. The E/Z ratio of thedouble bond in the nitrile group containing side chain can be influencedto a certain extent by the solvent-base combination empolyed in thisreaction. Aprotic conditions favor a higher content of Z-isomers than doprotic conditions. The formation of β,γ-unsaturated nitrile-isomersoccurs to a considerable extent in the decarboxylation of the alkylidenecyanoacetic acids prepared from cyanoacetic acid or esters and theoxo-compounds.

As the examples will demonstrate, the nitriles of this invention exhibita wide variety of odor effects. They can be used alone as fragrances perse or they can be used as components of a fragrance composition. Theterm "fragrance composition" is used to denote a mixture of compoundsincluding, for example, natural oils, synthetic oils, alcohols,aldehydes, ketones, esters, lactones, ethers, hydrocarbons and otherclasses of chemical compounds which are admixed so that the combinedodors of the individual components produce a pleasant or desiredfragrance. Such fragrance compositions or the novel compounds of thisinvention can be used in conjuction with carriers, vehicles or solventscontaining also, as needed, dispersants, emulsifiers, surface-activeagents, aerosol propellants and the like.

In fragrance compositions the individual components contribute theirparticualr olfactory characteristics, but the overall effect of thecomposition is the sum of the effect of each ingredient. Thus, thenitriles of this invention can be used to alter, enhance, or reinforcethe aroma characteristics of the other natural or synthetic materialsmaking up the fragrance composition, for example, by highlighting ormoderating the olfactory reaction contributed by another ingredient orcombination of ingredients.

The amount of nitrile which will be effective depends on many factorsincluding the other ingredients, their amounts and the effects which aredesired. It has been found that as little as 0.01% by weight ofcompounds of this invention can be used to alter the effect of afragrance composition. The amount employed will depend on considerationsof cost, nature of end product, the effect desired in the finishedproduct, and the particular fragrance sought, but normally will not bemore than about 30% by weight.

The compound disclosed herein can be used in a wide variety ofapplications such as, e.g., detergents and soaps; space deodorantsperfumes, colognes; after-shave lotions; bath preparations such as bathoil and bath salts; hair preparations such as lacquers; brilliantines,pomades and shampoos; cosmetic preparations such as creams, deodorants,hand lotions, and sun screens; powders such as talcs, dusting powders,face powder; as masking agents, e.g., in household products such asbleaches, and in technical products such as shoe polish and automobilewax.

The following examples illustrate the invention, which is not to beconsidered restricted thereto but is limited solely as indicated in theappended claims.

EXAMPLE 1

A mixture of 15 g (0.089 mole)2-formyl-p-menthane, obtained from (+)-p-1-menthene, (α)_(D) ²⁰ =+86.8°; via a Prins reaction withparaformaldehyde (as described in Bull. Soc. Chim. France 1960; 98)followed by hydrogenation and oxidation, 8 g cyanoacetic acid (0.094mole), 1 g ammonium acetate, 50 ml N,N-dimethylformamide and 50 mltoluene was refluxed with azeotropic removal of the water formed. Afterthe theoretical amount of water was collected the toluene was distilledoff and the residue was refluxed for 21/4 hr. The cooled reactionmixture was poured into water and extracted twice with ether. The etherlayers were washed with saturated KHCO₃ solution, then with saturatedNaCl solution and finally dried with Na₂ SO₄. After evaporation of theether, distillation of the residue yielded 14.5 g (0.076 mole=85%)isomeric mixture of 3-(1-methyl-4-isopropylcyclohexyl-2)acrylonitrileand 3-(1-methyl-4-isopropylcyclohexylidene-2)propanenitrile, b.p.92°-98° C. at 0.7 mm Hg, n_(D) ²⁰ =1.4805, with green, petit grain like,leathery, woody odour.

EXAMPLE 2

The procedure of Example 1 was repeated starting with2-formyl-p-menthane prepared from (-)-p-1-menthene, (α)_(D) ²⁰ -=80.6°,via the Prins reaction with paraformaldehyde. Obtained was 83% yield ofthe isomeric mixture of3-(1-methyl-4-isopropylcyclohexyl-2)acrylonitrile and3-(1-methyl-4-isopropylcyclohexylidene-2)propanenitrile, b.p. 77°-82° C.at 0.3 mm Hg, n_(D) ²⁰ =1.4792, with an odour similar to that of thenitrile mixture of Example 1.

EXAMPLE 3

To a suspension of 1.8 g. 80% sodium hydride (0.060 mole) in 40 mlN,N-dimethylformamide was added dropwise in the course of 20 minutes amixture of 10.5 g (0.060 mole) diethyl cyanomethylphosphonate and 10 mlN,N-dimethylformamide. The reaction temperature was maintained at 30° C.during the addition and for an additional 3/4 hour. The 10 g (0.060mole) 2-formyl-p-menthane used in Example 1 was added dropwise in 30minutes and the reaction mixture was kept at 40° C. for two hours,cooled and 10 ml acetic acid and 75 ml water were added respectively.The organic material was taken up in ether and washed with saturatedKHCO₃ solution, and with saturated NaCl solution and dried with Na₂ SO₄.After evaporation of the solvent, distillation yielded 9.5 g (0.050mole=83%) 3-(1-methyl-4-isopropylcyclohexyl-2)acrylonitrile, b.p.87°-89° C. at 0.6 mm Hg, n_(D) ²⁰ =1.4802, with green, watery, fattyodour.

EXAMPLE 4

Analogously to Example 3 was prepared2-n-butyl-3-(1-methyl-4-isopropylcyclohexyl-2)acrylonitrile from2-formyl-p-menthane used in Example 1 and diethyl1-cyanopentylphosphonate in 66% yield, with woody odour, b.p. 109°-114°C. at 0.3 mm Hg, n_(D) ²⁰ =1.4749.

EXAMPLE 5

Analogously to Example 1 was prepared ethyl2-cyano-3-(1-methyl-4-isopropylcyclohexyl-2)acrylate from2-formyl-p-menthane used in Example 1 and ethyl cyanoacetate in 73%yield, b.p. 110°-113° C. at 0.2 mm Hg, n_(D) ²⁰ =1.4828.

EXAMPLE 6

To a suspension of 2.6 g 80% sodium hydride (0.090 mole) in 50 mlN,N-dimethylformamide was added dropwise in five minutes 15 g (0.057mole) ethyl 2-cyano-3-(1-methyl-4-isopropylcyclohexyl-2)acrylateprepared in Example 5. The reaction temperature was kept at 40° C. forfour hours. Then 18.8 g (0.114 mole) 1-bromohexane was added in 15minutes at 40° C. and the mixture was stirred at 40° C. for 44 hours,cooled to room temperature, acidified with 10 ml acetic acid, dilutedwith 75 ml water and extracted with ether. The ether extracts werewashed with saturated KHCO₃ solution and saturated NaCl solution, thendried with Na₂ SO₄. After evaporation of the solvent 23 g residue wasobtained, which was taken up in 10 ml absolute ethanol and treated witha solution of 3,5 g potassium hydroxide in 15 ml absolute ethanol for 5minutes at 35° C. After evaporation of the ethanol by means of a rotaryevaporator the residue was taken up in water, acidified with dilute HClsolution and extracted with ether. After evaporation of the solvent thecrude cyanoacid was refluxed in 25 ml N,N-dimethylformamide for 2 hours.Distillation yielded 10 g (0.364 mole=64%)2-n-hexyl-3-(1-methyl-4-isopropylcyclohexylidene-2)propanenitrile withgreen fatty odour, b.p. 119°-121° C. at 0.2 mm Hg, n_(D) ²⁰ =1.4735.

EXAMPLE 7

To a mixture of 10 g (0.060 mole) 2-formyl-p-menthane used in Example 1,6.8 g (0.060 mole) ethyl cyanoacetate, 0.35 g acetic acid and 40 mldioxane was added, at 20° C., 0.5 ml piperidine. After stirring for anadditional 10 minutes at room temperature 0.5 g palladium on charcoalwas added and the mixture was hydrogenated at room temperature andatmospheric pressure untill the theoretical amount of hydrogen was takenup. The catalyst was removed by filtration and after evaporation of thesolvent the mixture was taken up in ether, washed with water, dilutehydrochloric acid, saturated KHCO₃ solution and saturated NaCl solutionrespectively and dried with Na₂ SO₄ . Distillation yielded 12 g (0.045mole=75%) ethyl 2-cyano-3-(1-methyl-4-isopropylcyclohexyl-2)propionate,b.p. 121°-127° C. at 0.4 mm Hg, which was saponified and decarboxylatedanalogous to the procedure of Example 6. Obtained was 69%3-(1-methyl-4-isopropylcyclohexyl-2)propanenitrile with fruity greenwoody odour, b.p. 87°-89° C. at 0.4 mm Hg, n_(D) ²⁰ =1.4670.

EXAMPLE 8

Analogously in Example 2 was prepared3-(1-methyl-4-isopropylcyclohexenyl-6)-2-butenenitrile from6-acetyl-p-1-menthene, prepared by acetylation of (+)-p-1-menthene asdescribed in Brit. Pat. No. 870.001. {α}_(D) ²⁰ =+86.8°, and diethylcyanomethylphosphonate, in 68% yield with woody cuminic odour. B.p.80°-83° C. at 0.5 mm Hg, n_(D) ²⁰ =1.4991.

EXAMPLE 9

Analogously to Example 2 was prepared2-methyl-3-(1-methyl-4-isopropylcyclohexenyl-6)-2-butenenitrile from6-acetyl-p-1-menthene, obtained by acetylation of (-)-p-1-menthene,{α}_(D) ²⁰ =-80.6°, and diethyl 1-cyanoethylphosphonate in 44% yieldwith cuminic greenish floral odour, b.p. 88°-92° C. at 0.3 mm Hg, n_(D)²⁰ =1.4948.

EXAMPLE 10

Analogously to Example 2 was prepared3-(1-methyl-4-isopropylcyclohexenyl-2)-2-butenenitrile from2-acetyl-p-1-menthene, prepared by alkaline isomerization (cf. Ber. 100,1892 (1967) for 2-acetyl-3-carene) of the 6-acetyl-p-1-menthene used inExample 8 and diethyl cyanomethylphosphonate in 68% yield with woodycinnamic odour. B.p. 96°-101° C. at 0.4 mm Hg, n_(D) ²⁰ =1.4981.

EXAMPLE 11

Analogously to Example 1 was prepared an isomeric mixture of3-(3-methyl-6-isopropenylcyclohexenyl-4)acrylonitrile and3-(3-methyl-6-isopropenylcyclohexenylidene-4)propanenitrile from2-methyl-5-isopropenyl-3-cyclohexenecarbaldehyde (Ber. 93, 2673 (1960))and cyanoacetic acid in 67% yield with greenish leathery woody odour,b.p. 78°-84° C. at 0.3 mm Hg, n_(D) ²⁰ =1.5040.

EXAMPLE 12

Analogously to Example 1 was prepared an isomeric mixture of3-(1-methyl-4-isopropenylcyclohexenyl-6)acrylonitrile and3-(1methyl-4-isopropenylcyclohexenylidene-6)propanenitrile from2-methyl-5-isopropenyl-2-cyclohexenecarbaldehyde (Bull.Acad.Polon.Ser.Sci.Chim. 13, 751 (1968) and cyanoacetic acid in 27% yield withbasilicum, fennel like odour, b.p. 86°-90° C. at 0.2 mm Hg, n_(D) ²⁰=1.5294.

EXAMPLE 13

A perfume composition is prepared by admixing the following ingredients:

    ______________________________________                                        200    bergamot oil                                                           100    lemon oil                                                              60     Vertofix (IFF)                                                         50     lavender oil                                                           50     alpha-hexylcinnamic aldehyde                                           50     hydroxycitronellal                                                     50     benzyl acetate                                                         50     gamma-methylionone                                                     40     patchouli oil                                                          40     geranyl acetate                                                        40     phenylethyl alcohol                                                    30     amyl salicilate                                                        30     musk-ambrette                                                          30     sandalwood oil                                                         20     cinnamic alcohol                                                       20     ylang-ylang oil I                                                      20     geranium oil, Bourbon                                                  20     cinnamon oil                                                           20     oakmoss absolute decolorised                                           15     Celestolide (IFF)                                                      10     cumarine                                                               10     dihydromyrcenol                                                        10     isoeugenyl acetate                                                     10     undecylenic aldehyde - 10%-sol.                                        5      styrallyl acetate                                                      5      Aurantiol (Schiff's base hydroxycitronellal-methyl                            anthranilate)                                                          5      cyclamenaldehyde                                                       10     isomeric nitrile mixture of Example 12                                 1000                                                                          ______________________________________                                    

The addition of 10% of the nitrile mixture of Example 12 gives a clearand desirable effect.

EXAMPLE 14

A perfume composition is prepared by admixing the following ingredients:

    ______________________________________                                        160    linalol                                                                100    cedarwood oil                                                          100    gamma-methylionone                                                     70     geraniol                                                               70     citronellol                                                            60     alpha-amylcinnamic aldehyde                                            50     benzyl acetate                                                         50     Vertenex (IFF)                                                         50     amyl salicilate                                                        40     phenylethyl alcohol                                                    40     Lyral (IFF)                                                            30     Celestolide (IFF)                                                      30     musk-ambrette                                                          20     cananga oil                                                            20     Lilial (Givaudan)                                                      20     oakmoss absolute                                                       15     Dimethylbenzylcarbinyl acetate                                         15     dihydromyrcenol                                                        10     litsea cubeba-oil                                                      10     cinnamon leaf oil                                                      5      Aurantiol (Schiff's base hydroxycitronellal-methyl                            anthranilate)                                                          5      laurylaldehyde                                                         5      methylnonylacetaldehyde                                                5      anisic alcohol                                                         15     isomeric nitrile mixture of Example 1                                  1000                                                                          ______________________________________                                    

The addition of 1,5% of the nitrile mixture of Example 1 gives a clearand desirable effect.

I claim:
 1. A mixture of the chemical compounds having the generalformulae: ##STR9## wherein R₁ and R₂ are hydrogen or alkyl radicals of 1to 6 carbon atoms and having between them a carbon number of 6 or lessand where the same substituents are present on each compound.
 2. Amixture of the chemical compounds having the general formulae: ##STR10##